Print recording material reservoirs equipped with memory devices, such as ink cartridges, have come to be used. In the memory device are stored, for example, data relating to the amount of printing/recording medium (“ink”), data relating to the type of ink, and information as to the year and date the ink cartridge was manufactured. In color printers, ordinarily at least four colors of ink are used, namely cyan ink, magenta ink, yellow ink, and black ink. Accordingly, a printer is equipped either with two ink cartridges, namely a black ink cartridge and a color ink cartridge, or with four ink cartridges, with one cartridge being for each color.
Further, to reduce the number of signal lines connecting each memory device provided on an ink cartridge with a control circuit, a technique is known whereby the signal line that identifies each memory device is eliminated, and a bus connection is used in which each memory device is connected using a common bus. With this technique, an identifying figure that has been uniquely assigned to each memory device is used to specify (identify) each bus-connected memory device.
However, with the bus connection format, the problem arises that, although the removal of an ink cartridge can be detected, when a plurality of ink cartridges are removed at the same time, it is impossible to identify which ink cartridge has been removed. Moreover, when communication between each memory device provided on an ink cartridge and the control circuit of the printer does not occur correctly, it cannot be ascertained in which memory device (ink cartridge) a malfunction has developed; the user must detach all of the ink cartridges to confirm their operation.